Matrix switch with improved actuator translating arrangement

ABSTRACT

An open contact matrix is disclosed having a printed wiring card as one of the basic elements thereof; the printed wiring card includes a plurality of fixed contacts and a corresponding plurality of movable contacts extending from the wiring card. A frame is provided for supporting an array of operating members, which are solenoid driven, for selectively moving an actuator above predetermined sets of movable contacts to close them on to their corresponding fixed contacts.

United States Patent Maruscak et al.

MATRIX SWITCH WITH IMPROVED ACTUATOR TRANSLATING ARRANGEMENT Inventors: John Maruscak; George McRae Hendry, both of Brockville, Ontario, Canada GTE Automatic Laboratories Incorporated, Northlake, 111.

Filed: July 18, 1973 Appl. No.: 380,430

Assignees US. Cl. 200/175, 335/113 Int. Cl. H0lh 63/33 Field of Search 200/1 R, 175, 176, 177, 200/178, 179; 179/18 A, 18 GE, 18 GF; 335/106113,115,116,117,112,113

References Cited UNITED STATES PATENTS 7/1950 Hickman ass/113x Sept. 24, 1974 2,942,068 6/1960 McCarthy et a1 200/175 3,529,113 9/1970 Vazquez et a1. r 200/175 3,551,631 12/1970 Vazquez et a1. r 200/175 3,643,053 2/1972 Grundig 335/111 X 3,678,422 7/1972 Reimer 335/112 Primary Examiner-James R. Scott Attorney, Agent, or Firm-David W. Heid [5 7 ABSTRACT An open contact matrix is disclosed having a printed wiring card as one of the basic elements thereof; the printed wiring card includes a plurality of fixed contacts and a corresponding plurality of movable contacts extending from the wiring card. A frame is provided for supporting an array of operating members, which are solenoid driven, for selectively moving an actuator above predetermined sets of movable contacts to close them on to their corresponding fixed contacts.

5 Claims, 19 Drawing Figures rfr' ri va ri rirr PATENTED 398380239 SHEH 1 0F 5 n n in I o :MIMIM PAIENIEDSEPZMQH 3,838,239

SHEET 2 0F 5 MATRIX SWITCH WITH IMPROVED ACTUATOR TRANSLATING ARRANGEMENT BACKGROUND OF THE INVENTION This invention relates generally to a matrix arrangement for closing predetermined sets of contacts arranged in a cross coordinate array. In particular, the invention is directed to a cross coordinate switch useful in connecting speech paths in a telephone switching system. Switches of the type disclosed herein are sometimes commonly referred to as crossbar switches, and perform a switching function in the modern automatic telephone switching systems.

Some of the earlier crosspoint switches, such as that disclosed in US. Pat. No. 3,445,795 issued May 20, 1969 to Holtfreter et a1, employed an arrangement of select units and hold units, and to keep the selected crosspoint closed it is necessary to maintain current flow through the hold magnet assembly. It is undesirable in modern switching systems to require that a holding current for each crosspoint be maintained during the connection. A more preferable switching technique is to provide crosspoint switches in which a voltage pulse or pulses are used to close or open the crosspoints.

With this in mind, several crosspoints switches have been devised in which no holding current is required; merely a series of pulses are used to actuate the crosspoint and it maintains its actuated condition until further pulses are used to break down the connection. Crossbar switches illustrative of this type of contact actuation and release are illustrated in, for example, US. Pat. No. 3,529,113 issued to Vazquez, et al. on Sept. l5, 1970. In this crossbar switch arrangement tightly wound coil springs are used to provide connections at selected crosspoints. A somewhat similar crossbar switch which employs a pulsed connection and release arrangement is shown in US. Pat. No. 3,643,053 issued to Grundig on Feb. 15, 1972. In the Vazquez patent the mobile contact member which is being moved into engagement with the stretched spring, is also a coiled spring which extends upward from the printed circuit board. During the operation and release of the crosspoint in the Vazquez arrangements, the coils of the associated mobile contact element tend to wear the select and connect bars during the operation and release since the spring is moving across the select and connect bar during the'connection and release. This problem has been recognized and in the US. Pat. No. 3,551,631, issued to Vazquez et al. on Dec. 29, 1970, an L-shaped opening is included in the switch in an attempt to reduce the wear of the driving teeth of the connection bar which would occur if the mobile contact were allowed to return to its release position without the benefit of the L-shaped guide. However, this L-shaped guiding opening does not eliminate the wear on the select and connect bars during the operation of the crosspoint. A further disadvantage of the Vazquez arrangements is that the contact area is limited. The contact which is being made between the movable spring member and the fixed spring member is in a point to point contact giving limited area.

SUMMARY OF THE INVENTION In the present invention a cross coordinate switch is provided which allows the crosspoint to be made by including on a printed circuit board the fixed and movable contacts, the movable contacts preferably comprising flat spring members. The contact areas of the flat spring members and likewise the fixed contact areas on the printed wiring card may be plated or otherwise coated with suitable contact metals or, as an alternative, discrete contacts of suitable composition may be welded, soldered or otherwise affixed to either or both the flat spring members and the fixed contact areas. These flat spring members provide a greater area of contact surface and hence a better connection than that provided in the Vazquez or Grundig arrangements cited previously. In the present invention an acutator, having a cam surface for closing the movable contacts onto the fixed contacts, is slidably supported above the printed circuit board on a frame, and the camming of the fiat springs against the actuator during operation and release produces only minimal wear.

The actuator in the present invention includes a link member pivotally attached thereto, with a finger extending upward from the free end of the link member. A select and connect bar are positioned on the frame above the actuator to cooperate with the finger. With the proper sequence of operation of the select and connect bars in cooperation with the finger, the actuator is moved from a first to a second position to operate the predtermined crosspoint. Preferably, the select and connect bars are made from a plastic material, as is the actuator, the link member and finger portion thereof and hence the operation of the crosspoint produces very minimal wear on the select and connect bars.

The cross coordinate matrix of the present invention is mounted on a plug-in printed circuit board which allows fast and simple replacement of the matrix if for some reason there should be a failure at any of the crosspoints. On the printed circuit board is mounted a frame which supports a plurality of solenoids for operating individual ones of an orthogonal array of operating members. The frame also supports an actuator above each crosspoint on the printed circuit board.

A cover is included over the frame and serves to secure the solenoids within the frame and also serves to prevent extraneous matter from entering the matrix and contaminating the switch crosspoints. The cover also serves to hold the connect bars and select bars into place on the upper surface of the frame, thereby also rendering the matrix switch indifferent to the attitude in which it may be mounted.

In a cross co-ordinate switch with a plurality of crosspoint contact sets arranged in columns and in rows, as in the Vazquez switch or as in the switch herein described, the requirement is to provide a means of actuating the contact set at any desired crosspoint without affecting all other crosspoints whose switching-on or switching-off is not desired at that time. For purposes of explanation, a typical desired crosspoint may be thought of as residing in a desired column of crosspoints designated C C and the same desired crosspoint may be thought of as residing in a crosscoordinate row of crosspoints designated R, R,.

The desired crosspoint may therefore be defined as that one residing at the intersection of the desired column and the desired row and may be exemplified by crosspoint C,,R,,.

The technique used for isolating a desired crosspoint out of all others in a cross co-ordinate array involved first the selection of the column in which the desired crosspoint resides. Subsequent to this selecting action a connecting action occurs which relates to all the crosspoints in the row cross coordinate to that of the column previously selected but which will materially affect only that crosspoint at the intersection of the desired column and row because of some consequence of the selecting action which has previously occurred.

In other words, the actuation of the set of contacts located at crosspoint C,,R,, involves the prior selection of crosspoints C, C, and subsequent connection action along crosspoint row R, R,. It should be noted that the act of selection, as herein employed, is exerted upon every one of an entire column of crosspoints C, C, while the action of connection is exerted upon only one desired crosspoint residing in that column C, C

The selection action referred to must necessarily cause some significant change of status at each of crosspoints C, C, in the desired column. This change of status involves a physical displacement and the consequent expenditure of energy, and the overall energy requirement for the selection operation will be not less than the sum of that energy consumed at all of crosspoints C, C Moreover if any energy must be stored at each of crosspoints C, C, as a consequence of the selecting operation, as for instance to assist in their ultimate return to their normal unselected position or status, the total energy requirement for the selection action will increase to the point where it may become the major component of the overall energy requirement for operation of the matrix switch. Energy storage, in the foregoing context, may be achieved by the deflection or stressing of springs or spring-like elements.

The total time required to switch on the contact set located at one desired crosspoint is at least the sum of that required for select and connect operations. Where fast switching rates are required, as for instance in modern telephone systems, energy must be supplied to the switching arrangement at a rate sufficient to accomplish the switching sequence of operation within a definable maximum acceptable elasped time. The energy requirements referred to above, plus the time limits herein referred to, together define the minimum power requirement for satisfactory operation of the matrix switch.

One of the objects of the present invention is to provide economy of operation in conjunction with highspeed switching, by minimizing the energy required to operate the crosspoint switch. This results from an improved selection arrangement in which no energy is stored at any crosspoint location in the course of the selection operation. In other words, apart from minimal losses due to increased friction, such an arrangement will consume no more energy in selecting, e.g., crosspoints than in selecting, e.g., 5 crosspoints. Further, in such an improved arrangement, selection energy requirements become comparable to or even less than connection energy requirements.

Another object of the present invention is to provide the simplicity, ease of maintenance and the manufacturing economies associated with the standardization of components both within the matrix switch and in the associated circuitry for controlling and powering the selection and connection functions of the matrix switch. The object cited is achieved because selection now requires no more power than connection and the use of identical power and circuit components is thereby made possible.

Another object of the present invention is to provide complete flexibility for optimum arrangement of the matrix switch crosspoint array for any particular switching system requirement. Each crosspoint can be thought of as a module and, for any particular switching application, such a plurality of modules may be employed in each column and such a plurality of modules may be employed in each row as best suits the requirements of the aforesaid specific application, and all without significant alteration of the energy input requirement of the switch nor of the timing characteristics of the switch, notwithstanding variation in such pluralities as from one application requirement to another application requirement. Such requirements are not limited to those presented by modern telephone switching systems. For instance, a single module l select X 1 connect) inherently constitutes a latching relay which may remain indefinitely in the latched mode for no energy is consumed during the latched mode and no forces are stored or exerted other than those of the pressure on the moving contacts to ensure reliable connection at the contact interfaces. Similarly, a l X 10 array (1 select X 10 connect) would provide a bank of 10 latching relays of which one, any combination thereof or all could be operated or released at any one time and the switching functions thereof could be individually unique or grouped in any desired combination or arrangement by suitable arrangement of the circuit paths to the fixed and moving contacts.

Another object of the present invention is to provide an improved crosspoint matrix mounted on the printed circuit board which may be easily removed and installed for operation in a telecommunication switching system.

Another object of the present invention is to provide a crosspoint actuating arrangement in which a floating link is pivotally connected to the actuator, and thereby any mechanical loading on the link is eliminated when the crosspoint is in the operated position.

Another object of the present invention is to provide a projection from the frame above the free end of the movable contacts to limit the upward travel of the contacts when they are in the unoperated position.

These and other objects of the present invention will best be understood by reference to the description of the invention which follows.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is an exploded perspective view of the major building blocks of the crosspoint matrix of the present invention. Part of the printed circuit board and cover portion of the switch have been shown in phantom.

FIG. 2 is a top plan view of one of the crosspoints of the present invention with the select and connect bars removed.

FIG. 3 is a view of the crosspoint of FIG. 2 taken along the lines 33 in FIG. 2.

FIG. 4 is a view of the crosspoint of FIG. 2 taken along the section 4-4 in FIG. 2.

FIG. 5 is a top plan view of the link member employed in the present invention.

, FIG. 6 is a view of the link member taken along lines 66 of FIG. 5.

FIG. 7 is a top plan view of a typical crosspoint of the present invention with the select and connect bars in place in the actuator and link illustrated in the rearward or unoperated position.

FIG. 8 is a top plan view of a typical crosspoint showing the first step in operation of the crosspoint.

FIG. 9 is the top plan view of a typical crosspoint showing the second step in the operation of the crosspoint.

FIG. 10 is a top plan view of a typical crosspoint in which the third step actuation of crosspoint has been illustrated.

FIG. I1 is a top plan view of the typical crosspoint showing the last step of the operation of the crosspoint.

FIG. 12 is a top plan view of a typical crosspoint illustrating the position of the link member during release of the crosspoint.

FIG. 13 is a section view taken along the line I3-13 of FIG. 1.

FIG. 14 is a section view taken along the line 14-14 of FIG. 13.

FIG. 15 is a top plan view of an alternative embodiment of the crosspoint actuation arrangement of the present invention.

FIG. 16 illustrates the first step in the release of the alternative crosspoint embodiment.

FIG. 17 illustrates the second step in the release of the alternative crosspoint embodiment.

FIG. 18 illustrates the third step in the release of the alternative crosspoint.

FIG. 19 illustrates the final step in the release of the alternative crosspoint.

DESCRIPTION OF THE PREFERRED EMBODIMENT The invention will best be understood by reference to the drawing figures, wherein now referring to FIG. 1, it will be noted that the matrix switch includes a printed wiring board 1 having groups of movable and corresponding fixed contact sets indicated by reference character 2. A portion of the printed wiring board 1 is shown in phantom view and it should be understood that there would be a continuing row and column configuration of movable and fixed contact sets 2, and in this particular embodiment there would be eight rows and eight columns of contact sets 2. The movable and fixed contact sets 2 will be described in detail subsequently, however they are illustrated in FIG. 1 to give the proper perspective of their arrangement on printed wiring board 1. A second major portion of the matrix switch is the frame 3. An orthogonal array of operating members is supported on frame 3, and as viewed in FIG. 1, those members aligned in the rows are called connect bars and are designated by reference character 7. Connect bars 7 are individually operated by connect solenoids 6, one solenoid 6 being provided for each connect bar 7. In a similar manner, a plurality of select solenoids 5 are supported on frame 3 and are used to engergize the plurality of select bars 4. The matrix switch is arranged such that for each intersection of a select and connect bar there is a corresponding movable and fixed contact set 2. The movable contact portion of the set is closed against associated fixed contact set by a movement of an actuator, which will be more fully disclosed in later drawing figures, from a first or rest position to its second or operated position by the proper sequence of operation of the select bar 4 and connect bar 7 at the particular crosspoint. It willbe noted in FIG. 1 that the fixed contacts 12 of the movable and fixed contact sets 2 are brought out to tabs 9 by circuit paths 10. Printed wiring board I is what is termed as a double sided board, and paths (not shown) on the opposite side of the board are used to make electrical connections from the movable contacts II to tabs (not shown) on the other side of the board. All of the movable contacts II are electrically connected in common in a column basis as seen in FIG. I, and all of the fixed contacts 12 are electrically connected in common on a row basis. Hence it will be appreciated that an electrical connection may be made from any row to any column by appropriately pulsing the row and column solenoids which intersect at the desired crosspoint.

A suitable number of holes 13 are provided in printed wiring board I so that self-tapping screws (not shown) may be passed from the underside of printed wiring board I through holes 13 to secure frame 3 rigidly to printed wiring board 1. It will also be noted that cover 14 includes holes 15 so that similarly self-tapping screws I6 may be passed through holes 15 and secure the cover 14 over top of frame 3. Frame 3 includes a rim 17 which completely encircles the outer perimeter of the upper portion of frame 3, and serves to support cover 14 slightly above the orthogonal array of select bars 4 and connect bars 7. Cover 14 includes along two sides thereof extensions 40 extending downward therefrom. Extensions 40 are positioned such that upon placement of cover 14 over frame 3 they hold the solenoids securely in place in frame 3. Select bars 4 are slidably supported on the floor 18 of frame 3 and connect bars 7 are slidably supported just clear of the array of select bars 4.

In order to better understand the operation of an individual crosspoint, at this point attention is directed to FIG. 2, which is a top plan view of one of the crosspoints of the matrix switch shown in FIG. 1 with the select and connect bars for that crosspoint removed so that it is easy to see the remaining crosspoint actuation parts. First it will be noted that actuator 19 is slidably supported on floor 18, actuator 19 having been snapped into a pair of slots 20. Actuator 19 may be moved forward and back within slots 20, actuator 19 being illustrated in its forwardmost position in FIG. 2. The total supporting arrangement for actuator 19 is better illustrated in later drawing figures. Again referring to FIG. 2, it will be noted that actuator 19 includes a link member 2I which is pivotally connected to a post 22 of actuator 19. The free end of link member 21 includes an upward extending pin 23 which, as will be described later cooperates with select bar 4 and connect bar 7 in the actuation of the crosspoint. Link member 21 is free to pivot about post 22 and is supported on a platform 24. Arcuate portion 45 of floor 18 is also clearly shown in FIG. 2. Arcuate portion 45 is so shaped that it prevents pin 23 from becoming disengaged from trapping zone 47 of connect bar 7 during the time of travel when pin 23 is near its forward most portion of travel. Further explanation of this operation is included subsequently.

Now referring to FIG. 3, there it will be seen that the major portion of actuator 19 rests below the surface of floor 18. The two outer edges of actuator 19 extend upward and form a pair of wings 25 which includes tabs 26 on the free ends thereof. With this arrangement, actuator 19 may be inserted from beneath floor 18 and upon tabs 26 passing through the upper surface of floor 18 the tabs 26 retain actuator 19 in slots 20. Also in FIG. 3 it will be observed that for each movable contact 11 there is a fixed contact 12 on printed circuit board 1. Cam surface 46 of actuator 19 serves to press mov able contacts 11 into engagement with their associated fixed contacts 12 when actuator 19 is moved to the forward position. The fixed contacts shown are of the op tional discrete type, affixed onto the printed circuit board contact areas. For some applications of the matrix switch, suitably plated fixed contact areas on the printed wiring card will suffice. In FIG. 3, it will be noted that link 21 rides on platform 24 which supports link 21 during its movement in the operation of the crosspoint. Frame 3 includes an oblong opening 27 which allows actuator 19 to be moved from its full forward to its full rearward position since the larger portion of post 22 extends through frame 3. Adjacent each crosspoint there is provided a shelf 28 which is an upper projection from frame 3, shelf 28 servingto support the connect bar 7 which cooperates with that particular row of crosspoints, at a height just clear of the select bars 4, thereby avoiding friction or wear between select bars 4 and connect bars 7.

Now referring to FIG. 4, a crosspoint is shown with the actuator 19 in a forward position wherein movable contact 11 has been pressed into engagement with fixed contact 12 through the interaction between cam surface 46 and movable contact 11. It will also be observed that there is a projection 29 which extends downward from frame 3, the purpose of projection 29 being to limit the upward travel of movable contact 11 when actuator 19 has moved from its forward position as shown in FIG. 4 to the rearward position. By building in projection 29 contact bounce is severely limited since the upper movement of movable contact 11 is dampened when it springs upward during the release of a crosspoint.

Link member 21 is shown in top plan view in FIG. and is therein illustrated to show a clear unencumbered view of the link member part from the remainder of the switch. In a similar manner it has been shown in FIG. 6 as a view taken along line 66 of FIG. 5.

At this point the operation and release of a typical crosspoint will be described and in reference thereto FIGS. 7 through 12 will be referred to during the explanation. FIG. 7 illustrates a typical crosspoint of the matrix, FIG. 7 being a much enlarged view of the crosspoint. Referring to FIG. 7, it will be seen that actuator 19 is in the rearward position, hence the crosspoint contacts associated therewith are open. The select bar 4 and connect bar 7 intersecting at this crosspoint are also shown in their unoperated position. At this point it should'be noted that select bar 4 includes a first projection 30 and a second projection 31 which are on opposite sides of pin 23 of link 21. It will be noted that the side of first projection 30 adjacent to pin 23 is relatively straight and substantially perpendicular to the longitudinal axis of select bar 4, however second projection 31 tapers in a camming surface 32 which lies with an angle from the longitudinal axis of select bar 4. The function of camming surface 32 will be described subsequently when the release of the crosspoint is described.

The first step in the operation of the crosspoint is illustrated in FIG. 8 where it will be noted that connect bar 7 is first moved as indicated by the arrow by its associated connect solenoid 6 against the spring force of its solenoid to the position shown in FIG. 8. It will be noted that pin 23 is now in line with the upper leg or trapping zone 47 of the U-shaped opening 33 and may be moved into the upper leg of the opening by select bar 4. The next step in the operational sequence is illustrated in FIG. 9 wherein the solenoid for select bar 4 is pulsed and select bar 4 moved as indicated by the arrow to the position shown in FIG. 9, thereby carrying pin 23 into the upper leg or trapping zone 47 of U- shaped opening 33. At this point the operating pulse which was previously applied to connect solenoid 6 ceases and connect bar 7 is then returned to the unoperated position shown in FIG. by the spring associated with the connect solenoid. In FIG. 10 it will be noted that upon release of connect bar 7 pin 23 which was moved into the upper leg or trapping zone 47 of the U-shaped opening 33 of connect bar 7 has been moved forward which of course translates actuator 19 to its forward position and operates the crosspoint. It will be noted in FIG. 10 that arcuate portion 45 of floor 18 keeps pin 23 in trapping zone 47 (not numbered in FIG. 10) after pin 23 is moved forward beyond the free end of first projection 30 of select bar 7. Thus it is insured that pin 23, and hence actuator 19, will be moved forward and the crosspoint actuated by the release of connect bar 7. Now that pin 23 has been moved forward it is no longer necessary for select bar 4 to be retained in its energized position and hence a pulse to select solenoid 5 has ceased. Select bar 4 is returned to its unoperated position by the spring associated with that solenoid.

FIG. 11 shows the crosspoint in its operated position wherein select bar 4 has been returned to its unoperated position as indicated by the arrow. This completes the operation of a typical crosspoint and it will be appreciated at this point the crosspoint has been closed and will remain closed without maintenance of holding current since the solenoids are now both in their unenergized position.

In order to open the contacts on any of the crosspoints, it is only necessary to apply a single voltage pulse to the solenoid in the row containing the connect bar which intersects the crosspoint to be opened. In a typical operation of a matrix by a common control system, the crosspoint may be maintained in its operated position even though the talking path which included the crosspoint has been broken and the conversation is no longer occurring. This is possible because once the former talking path has been sensed to be non-used, the row which contains the crosspoint formerly used for that talking path may again be used merely by again pulsing the solenoid which is connected to the connect bar in that row. This pulse may be the first (connect) pulse of an actuating sequence for any crosspoint in the same row and this is a valuable advantage of the preferred embodiment herein described. In other words, the first step in operating any crosspoint in a row is also the step which will open any previously-operated crosspoint in that row. A separate connect re1ease" pulse is not required except where other conditions in affiliated switching circuitry might render such a separate pulse desirable. This will be better understood by reference to FIG. 12 wherein it is shown that the crosspoint is in the process of being opened by energizing connect solenoid 6 which is moving the connect bar 7. As shown in FIG. 12, connect bar 7 is moving in the direction of the arrow and is only partially moved toward its total rearward movement. In this manner connect bar 7 is pulling pin 23 along cam surface 32 which will, after its final movement to the full degree, move pin 23 into the position shown in FIG. 7. During the movement of connect bar 7 as shown in FIG. 12, arcuate portion 45 prevents movement of pin 23 to the right, and hence out of trapping zone 47, so that camming surface 32 and trapping zone 47 will return pin 23 to the neutral position. After connect bar 7 has returned pin 23 to the position as shown in FIG. 7, then pin 23 is in a neutral position and another crosspoint in the row or column containing either the connect bar 7 or select bar 4 may be energized without again operating this particular crosspoint. This is so because pin 23 is now out of the upward leg or trapping zone 47 of U- shaped opening 33 and a subsequent re-energizing of connect bar 7 will not pull pin 23 and link 21 forward to operate that particular crosspoint.

In FIG. 13, which is an enlarged sectional view taken along the lines 13-13 of FIG. 1, the relationship between connect solenoid 6 and connect bar 7 is illustrated. Connect solenoid 6 is supported in the matrix switch by the combination of frame 3 and extension 40 of cover 14, which when held together as mentioned previously by screw 16, clamps solenoid 6 into place. Each solenoid 6 includes a plunger 34 which is shown in FIG. 13 in its forward or unenergized position, and which is normally retained in this forward position by helical spring 35. Select solenoids are held into the matrix in the same manner as solenoid 6 and include a helical spring which normally retains the plunger which they include in the same relative position as is shown in FIG. 13. The select solenoids, their plungers and the helical springs used therewith are in all respects identical to the connect solenoids and their associated parts. Returning to FIG. 13, the free end of plunger 34 is terminated in a circular portion 36. As can be seen in FIG. 13, the upper part of section 36 is fitted into a semicircular opening 36 in connect bar 7. This fit between section 36 and a semicircular opening 37 allows the solenoid 6 to operate and release connect bar 7. It will be noted that the forward travel of plunger 34 is limited by the lower portion of section 36, which by virtue of spring 35 is forced into engagement with wall section 38 of frame 3. In order to establish a predetermined stroke for the connect bars, a semicircular depression or pocket 44 has been molded as a part of frame 3. The outer face 39 of the depression 44 determines the stroke of solenoid 6 since a lower portion of circular section 36 of plunger 34 will strike the outer face 39 upon its rearward travel when solenoid 6 has been energized.

In a like manner, the stroke of select solenoids 5 is also determined by similar wall and pocket faces (not shown) in frame 3. Hence it will be appreciated that the maximum stroke of select and connect bars may be determined by merely molding into frame 3 appropriately dimensioned pockets, for wall section 38 of frame 3 is actually the inner face of pocket 44.

FIG. 14 is a sectional view taken along the lines l4--l4 of FIG. 13, and illustrates plunger 34, circular portion 36 and their relationship with frame 3. Pocket 44 in frame 3 with its rear face 39, connect bar 7, and upper surfaces 18 of frame 3 are also illustrated.

FIG. illustrates an alternative embodiment for a crosspoint actuation arrangement. A modified select bar 41 is utilized in place of the previously described select bar 4. Referring to FIG. 15 it will be noted that select bar 41 rests on floor 18 of the frame 3 in the same manner as did select bar 4 however, select bar 41 includes two spaced apart projections 42 and 43. By comparing the select bar 4 with select bar 41 it will be noted that projection 42 is identical to projection 30 of select bar 4 however projection 43 is much smaller than second projection 31 of select bar 4 and in fact is substantially the same as projection 42. With the modified select bar 41 shown in FIG. 15, the operation of the crosspoint follows the sequence of steps previously illustrated in FIGS. 8 through 11. However the release of the crosspoint requires additional steps since select bar 41 does not include a camming surface, as did select bar 4, to return pin 23 into the neutral or unoperated position as illustrated in FIG. 7. It should also be pointed out that except for the modified select bar 41, the remaining elements of the alternative crosspoint illustrated in FIG. 15 are unchanged from those as illustrated in FIG. 7, and hence like reference characters have been used on the corresponding elements.

Referring to FIG. 16, the alternative crosspoint is shown in the actuated position, and the first step in the release of the actuated crosspoint is illustrated. This first step involves moving select bar 41 to the left as shown by the arrow. After select bar 41 has been moved to the position shown in FIG. 16, it will be noted that the pin 23 now lies above the spaced apart projections 42 and 43. The second step in the release of the crosspoint is illustrated in FIG. 17 wherein, as noted by the arrow, connect bar 7 has been moved downward which now brings pin 23 into the space between projection 42 and 43 of select bar 41. The third step in the release is illustrated in FIG. 18 wherein select bar 41 is returned to its normal position, the direction of movement being shown by the arrow. It will be recalled that this return action occurs by the release of the potential to the corresponding select solenoid, thus allowing the spring associated with that select solenoid to return the select bar 41 to the position illustrated in FIG. 17. Now that pin 23 is out of the reach of the trapping zone 47 of connect bar 7, the final step is to release the connect solenoid associated with the connect bar 7 for that crosspoint and allow it to return to its normal position moving in the direction of the arrow as illustrated in FIG. 19. Now both the select bar 41 and connect bar 7 have been returned to their normal or unenergized positions and the crosspoint is ready for use at a later time.

What is claimed is:

1. In a cross-coordinate switch including a printed circuit board having thereon fixed contacts and movable contacts extending from said board in engageable relationship with said fixed contacts; a frame supported on said printed circuit board; and an actuator slidably supported by said frame above said movable contacts, said actuator including a cam surface for pressing said movable contacts into an engagement with said fixed contacts upon movement of said actuator from a first to a second position, an improved actuator translating arrangement comprising:

a link member pivotally connected to said actuator,

said link member including a pin on one end thereof;

a connect bar having a trapping zone therein for selectively engaging said pin and moving said actuator means; and

a select bar having a pair of projections, one of said pair being selectively engageable with said pin for pivoting said pin into said trapping zone of the associated connect bar, and the other of said projections serving to pivot said pin out of engagement with said trapping zone, said select and connect bars cooperating with said pin on said link member to selectively move said actuator from said first to said second position and from said second to said first position.

2. The improved actuator translating arrangement as claimed in claim 1 wherein said second projection on said select bar serves as a cam surface to guide said pin therealong upon the movement of said connect bar from the operated to the unoperated position and thereby return said actuator means from said second to said first position.

3. The improved actuator translating arrangement as claimed in claim 1 wherein said frame includes a platform for slidably supporting said link member.

4. The improved actuator translating arrangement as claimed in claim 1 including a projection from said frame spaced above the free end of said movable contact to limit the upper travel of said movable contact.

5. The improved actuator translating arrangement as claimed in claim 1 wherein said frame includes a shelf for supporting said connect bar in operative relationship with said pin. 

1. In a cross-coordinate switch including a printed circuit board having thereon fixed contacts and movable contacts extending from said board in engageable relationship with said fixed contacts; a frame supported on said printed circuit board; and an actuator slidably supported by said frame above said movable contacts, said actuator including a cam surface for pressing said movable contacts into an engagement with said fixed contacts upon movement of said actuator from a first to a second position, an improved actuator translating arrangement comprising: a link member pivotally connected to said actuator, said link member including a pin on one end thereof; a connect bar having a trapping zone therein for selectively engaging said pin And moving said actuator means; and a select bar having a pair of projections, one of said pair being selectively engageable with said pin for pivoting said pin into said trapping zone of the associated connect bar, and the other of said projections serving to pivot said pin out of engagement with said trapping zone, said select and connect bars cooperating with said pin on said link member to selectively move said actuator from said first to said second position and from said second to said first position.
 2. The improved actuator translating arrangement as claimed in claim 1 wherein said second projection on said select bar serves as a cam surface to guide said pin therealong upon the movement of said connect bar from the operated to the unoperated position and thereby return said actuator means from said second to said first position.
 3. The improved actuator translating arrangement as claimed in claim 1 wherein said frame includes a platform for slidably supporting said link member.
 4. The improved actuator translating arrangement as claimed in claim 1 including a projection from said frame spaced above the free end of said movable contact to limit the upper travel of said movable contact.
 5. The improved actuator translating arrangement as claimed in claim 1 wherein said frame includes a shelf for supporting said connect bar in operative relationship with said pin. 